Method and Device for Managing Control Information in Nr V2x

3. The method of claim 1, wherein at least one of a configuration of the second SCI or a size of the second SCI is determined differently based on a value included in the first SCI.

4. The method of claim 1, wherein a plurality of candidate sizes for the second SCI are pre-configured.

5. The method of claim 4, wherein padding bits are added to a selected one of the candidate sizes for the second SCI until it is equal to a size of the first SCI, based on the number of the plurality of candidate sizes exceeding a format size budget of the second SCI.

6. The method of claim 4, wherein padding bits are added until a size of any one selected among the plurality of candidate sizes is equal to the largest candidate size among the plurality of candidate sizes, based on the number of the plurality of candidate sizes exceeding a format size budget of the second SCI.

7. The method of claim 1, wherein transmission of acknowledgment (ACK) feedback is skipped, based on the data being successfully decoded.

8. The method of claim 1, wherein the cast type indicator is 2 bits.

9. The first device of claim 1, wherein the cast type indicator is configured to indicate one of a plurality of cast types and HARQ feedback mode combinations including a first combination of Groupcast and ACK/NACK feedback mode, and a second combination of Groupcast and negative-only acknowledgment (NACK) feedback mode.

10. The first device of claim 1, wherein at least one of a size of the first type of SCI format or a size of the second type of SCI format is determined differently based on a value included in the first SCI.